Chicago Bears at San Francisco 49ers

FILE - In this Dec. 2, 2012 file photo, San Francisco 49ers quarterback Alex Smith warms up as 49ers head coach Jim Harbaugh, left, stands nearby before the start of an NFL football game against the St. Louis Rams in St. Louis. A person with knowledge of the trade tells The Associated Press that the Kansas City Chiefs have agreed to acquire Smith from San Francisco. The person spoke on condition of anonymity on Wednesday, Feb. 27, 2013, because the trade does not become official until March 12, when the NFL's new business year begins. (AP Photo/Tom Gannam, File)